Title :
A Bidirectional Readout Integrated Circuit (ROIC) with Capacitance-to-Time Conversion Operation for High Performance Capacitive MEMS Accelerometers
Author :
Lee, Sungsik ; Lee, Myunglae ; Jung, Sunghae ; Je, Changhan ; Park, Jiman ; Hwang, Gunn ; Choi, Changauck
Author_Institution :
Electron. & Telecommun. Res. Inst. (ETRI), Daejeon
Abstract :
In this paper, a bidirectional readout integrated circuit (ROIC) with capacitance-to-time conversion operation has been proposed and demonstrated for high performance capacitive micro-electro-mechanical system (MEMS) accelerometers, which is implemented by a 0.35-mum CMOS EEPROM process. For the desired performance of the proposed ROIC, a bidirectional time-to-digital conversion (TDC) method with a capacitance-to-time (C-T) conversion operation is employed for the detection of the directions. At the condition of the reference capacitance (CRef.) of 20 pF, the new ROIC shows the positive sign-bit (´1´) for the case of the sensor capacitance (CSen.) < 20 pF and the negative sign-bit (´0´) for the case of CSen. > 20 pF, which lead to the bidirectional accelerometer operation. Consequently, the new proposed ROIC exhibits the bidirectional readout operation by the bidirectional TDC operation with the C-T conversion.
Keywords :
CMOS memory circuits; EPROM; accelerometers; analogue-digital conversion; capacitive sensors; microsensors; readout electronics; CMOS EEPROM process; bidirectional accelerometer operation; bidirectional readout integrated circuit; bidirectional time-to-digital conversion method; capacitance-to-time conversion operation; capacitive MEMS accelerometers; capacitive micro-electro-mechanical system accelerometers; sensor capacitance; size 0.35 mum; Acceleration; Accelerometers; Capacitance; Capacitive sensors; Circuits; Latches; Microelectromechanical systems; Micromechanical devices; Signal resolution; Voltage;
Conference_Titel :
Sensors, 2007 IEEE
Conference_Location :
Atlanta, GA
Print_ISBN :
978-1-4244-1261-7
Electronic_ISBN :
1930-0395
DOI :
10.1109/ICSENS.2007.4388393